Table 5.
Chronological age predicted by the Demirjian and Nolla methods for four age-groups defined by cluster analysis
| Age-group | Demirjian | Age-group | Nolla | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| B | SE B | β | t | B | SE B | β | t | |||
| 4 to 8 years | Constant | 67.26 | 1.65 | 40.84*** | 4 to 10 years | 54.85 | 1.69 | 32.44*** | ||
| Predictor | 0.20 | 0.02 | .69 | 11.99 | 0.43 | 0.02 | .85 | 28.43*** | ||
| R = .688, R2 = .473, SEE = 0.69 | R = .846, R2 = .715, SEE = 0.80 | |||||||||
| F(1,410) = 143.71, p < .001 | F(1,322) = 808.14, p < .001 | |||||||||
| 95% confidence interval for B: .047 to 0.65 | 95% confidence interval for B: .191 to .220 | |||||||||
| Predicted chron. age = 67.26 + 0.20 x Demirjian’s score | Predicted chron. age = 54.85 + 0.43 x Nolla’s score | |||||||||
| 9 to 14 years | Constant | 4.02 | 7.855 | 0.51 | 11 to 15 years | 53.15 | 6.75 | 7.88*** | ||
| Predictor | 0.83 | .049 | .64 | 17.07*** | 0.59 | 0.04 | .65 | 15.22*** | ||
| R = .640, R2 = .410, SEE = 1.29 | R = .654, R2 = .428, SEE = 1.00 | |||||||||
| F(1,410) = 291.46, p < .001 | F(1,310) = 231.75, p < .001 | |||||||||
| 95% confidence interval for B: .208 to .262 | 95% confidence interval for B: .248 to .322 | |||||||||
| Predicted chron. age = 4.02 + 0.83 x Demirjian’s score | Predicted chron. age = 53.15 + 0.59 x Nolla’s score | |||||||||
| 15 to 18 years | Constant | 31.17 | 40.94 | 0.76 | 16 to 19 years | 59.68 | 59.44 | 1.00 | ||
| Predictor | 0.93 | .234 | .32 | 3.94*** | 0.78 | 0.32 | .24 | 2.46* | ||
| R = .324, R2 = .105, SEE = 1.08 | R = .237, R2 = .056, SEE = 1.20 | |||||||||
| F(1,410) = 15.49, p < .001 | F(1,102) = 6.05, p = .016 | |||||||||
| 95% confidence interval for B: .129 to .390 | 95% confidence interval for B: .072 to .675 | |||||||||
| Predicted chron. age = 31.17 + 0.93 x Demirjian’s score | Predicted chron. age = 59.68 + 0.78 x Nolla’s score | |||||||||
| 19 to 34 years | Constant | -122.97 | 809.89 | -0.15 | 20 to 34 years | -214.81 | 362.66 | -0.59 | ||
| Predictor | 2.14 | 4.58 | .05 | 0.47 | 2.50 | 1.90 | .147 | 1.33 | ||
| R = .047, R2 = .002, SEE = 2.28 | R = .147, R2 = .022, SEE = 2.16 | |||||||||
| F(1,410) = 0.22, p = .641 | F(1,79) = 1.74, p = .191 | |||||||||
| 95% confidence interval for B: -1.96 to 3.17 | 95% confidence interval for B: -.615 to 3.03 | |||||||||
| (Demirjian method not statistically significant, p > .05) | (Nolla method not statistically significant, p > .05) | |||||||||
*p < .05; ***p < .001.